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Container gardening tips

Home & Garden

Container gardening tips

Potting plants can be a complicated task, but this comprehensive guide to pots will take some of the guess-work out of this gardening style.

A guide to perfect pottingThe container: One oversize pot makes more of an impact than several smaller ones. Pick a pot that accomodates the plant roots snugly (otherwise they will expend too much energy to fill the pot at the expense of the whole plant). And choose a pot that harmonizes with the flowers and foliage (the warmth of terra-cotta echoes the peachy-pink flowers of Diascia, for example). Don't forget that a drainage hole is a must.

The soil: For annuals, use a soilless mix. For perennials, combine the mix with composted manure, 2:1. For succulents, use a commercial cactus mix. Before you plant a container, dampen the mix so it's moist but not wet.

The plants: As long as they share similar growing requirements, different types of plants -- annuals, perennials, herbs, vegetables, shrubs and trees -- can be grouped in one container. Water each plant an hour or so before planting to moisten the rootball.

• one tall plant that's roughly one-and-a-half to two times the height of the pot;

• two plants to cascade over the side but leave space to show off the pot; and

• five filler plants of contrasting textures and colours. Airy, branching or mounding, these shouldn't be more than two-thirds the height of the tall plant. Use them to create a miniature landscape. Remove each plant from its nursery pot and gently loosen the roots. Place the tall plant in your pot, slightly off-centre (and, if the pot will sit against a wall, at the back). Working outward, place the filler plants then the cascading ones. Top up the mix only to within an inch of the rim (to allow water to pool in the pot instead of running off), tampering it down around the plants. Finish by watering with a solution of transparent fertilizer, such as 6-16-5, to encourage root growth. Sprinkle a balanced, slow-release fertilizer onto the mix or add water-soluble 20-20-20 fertilizer every two to three weeks when you water.

4 watering tips1. Don't let plants wilt, but do allow the planting mix to dry out slightly. This toughens up plants, making them more resilient to moisture fluctuations.

2. Poke your finger an inch or two into the soil. If the soil feels dry, it's time to water.

3. Keep watering until the excess runs out the drainage hole. Ensure free drainage by placing a piece of screen or several flowerpot shards over the hole inside and elevate the container on bricks or pot "feet."

4. Succulents need less moisture than most plants. Before watering, lift the flowerpot: the lighter the container, the drier the soil.

All fired up about terra-cotta• Terra-cotta is good for plants. Because it's porous, it pulls excess moisture away from roots, allowing them to breathe.

• Weighty enough to withstand gusts of wind, terra-cotta pots make perfect planters for tall shrubs and trees. And hefty pots can be strategically placed to hold hoses safely away from flowerbeds.

• Even empty terra-cotta pots make beautiful garden accents. You can also use them as catchpots to camouflage plastic planters or line them and use them as serving bowls.

• Literally translated, terra-cotta means "baked earth." But all terra-cotta pots are not created equal -- recognizable by their deep earth-red colour, pots fired at higher temperatures are more durable.

• Terra-cotta is versatile. You can mix it with cast iron, wirework or galvanized metal, or combine weathered terra-cotta pots with new ones, glazed or textured pots with plain. Buy the best pots you can afford and build a collection, adding a few each year.

Tender winter carePots of tropical plants• Before bringing tropical plants inside, immerse them in a bucket of water for about five minutes, then skim off any insects that float to the surface. Check the drainage holes, too, for slugs.• With insecticidal soap, spray the foliage and drench the rootballs.• Place the plants in a sunny window, under lights or in a heated greenhouse.• Take cuttings to root over the winter.

Containers of mixed plants• Remove all the plants from their pots.• From annuals, take cuttings to root over the winter, then compost the discarded mix and plants.• Repot the perennials, shrubs and trees using fresh soilless mix and plastic pots.• Overwinter them in an unheated garage or shed and keep the mix covered with a layer of snow, replenishing it as necessary (during thaws, the snow provides moisture).

Terra-cotta pots• Empty and clean each pot.• To prevent moisture from pooling inside, then freezing and cracking the pots, stack and tilt small pots upside down and invert large planters. Ensure that the pots don't rest on a level surface, such as soil, pavement or deck. Try placing bricks underneath to shield pots from the soil or use pottery shards to prop up any containers left on the deck.